All publications herein are incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Cancer metastases may result from cancer cells growing directly into the tissue surrounding the tumor, cancer cells traveling through the blood stream to distant locations and/or cancer cells traveling through the lymphatic system to nearby or distant lymph nodes. There is no single test for detecting tumor metastasis in general. Routine blood tests detecting specific markers may indicate metastasis but the blood tests are often normal in subjects with advanced forms of cancer. Existing imaging techniques have their limitations as well and are expensive, time consuming. There is a need in the art for tests simple blood to detect cancer metastasis.
Herein, inventors show that cancer cells shed large oncosomes. Presence of large oncosomes or an increase in the number of large oncosomes in a sample obtained from a subject that has or had cancer may be indicative of tumor metastases. The large oncosomes include proteins and nucleic acids (such as DNA, micro RNA) that are either enriched in large oncosomes compared to smaller microvesicles or that are uniquely expressed in large oncosomes compared to smaller microvesicles.